I can't provide any advice on the suspension, but a few observations. That's a pretty serious tire size for the power you make. How high is the converter stall? I would throw everything you have at it and if it still dead hooks, adjust the suspension from there. If it cooks the tire, then back off in small increments.

General rule of thumb we follow for launch setup is throw all the power we can at it and back up from there. Then move up in increments of 250 RPM and tweak the suspension as we go.

FWIW, I know some setups making 2k hp and hooking up on a 15" wide tire.

 

I know it sucks because i see guys with less power and same tire spinning right off the hit and other guys having a hook then spin, and then some hook spin hook spin

Converter stalls around 7100

I have a feeling if i throw it all at it then ill spin but my driveshaft will be way too high

 

Add more air to rear tires.

 

that would give it more bite, what's your reasoning for more air?

 

Do any of you have a built in eye for wheel speed from a video??
I think my new data recorder is jacked up.
I sure don't, but I can't believe the numbers I'm getting???
Way too low to believe, even with a slow ass 60!!!!


.

 

Heres the runs from this weekend showing .25, .5 and accel g showing it hooking, letting go then hooking again

 

Seems like you didn't add enough pressure. It will also wrinkle the side walls less with more pressure. Bump it up to 8-9 and I bet it spins. Then lower them till they just spin a bit on the hit and go. Assuming its well below 2500lbs?

 

The whole reason i was going that low was too take bite away, i even looked at my wheelie bar sensor and it hit the bar hard and bounced a few times. More air would make it bite harder

 

Only up to a certain point. Yes, I know going from 5.5 to 5.7 will make it bite harder. I get it.

But going to 8-10-12psi etc will eventually make it spin. It will eventually apply more force to the center contact patch and less to the edges the more pressure you add. Some need more pressure than others, just give it what it wants. Bosses 7.80 rail liked 12lbs in the tire. I run 7lbs. At 6 it dead hooked and at 8.5 It spun a ton. At 7 it spun a little and hooked so here we are.

 

Only up to a certain point. Yes, I know going from 5.5 to 5.7 will make it bite harder. I get it.

But going to 8-10-12psi etc will eventually make it spin. It will eventually apply more force the center contact patch and less to the edges edges the more pressure you add. Some need more pressure than others, just give it what it wants. Bosses 7.80 rail liked 12lbs in the tire. I run 7lbs. At 6 it dead hooked and at 8.5 It spun a ton. At 7 it spun a little and hooked so here we are.

Ok i get what youre saying, cant hurt to try it

 

how much rear spread and how high is the bottom bar off the ground?

 

8" off the ground is bottom bar
Spread is 11.5 and 7.4

 

Typically as you get more rear bias, you need less IC length and you may also be able to get away with less rear spread. A few things to try:
1. lower the whole top bar 1 hole down.
2. Dump air off the shocks as soon as it leaves

The other thing is 46-4800 with that SLR is still what i’d consider a low starting line rpm and I wouldn’t be scared to try 52-5500. Last you might consider a new set of wheelie bars that are shorter(~70-75”) and stiffer to help get the tire turning easier. Your tire pressure at 5.5 is fine for what you’re running but wouldn’t be scared to go 5.3-5.4 considering the heavy rear bias. Good luck

 

Typically as you get more rear bias, you need less IC length and you may also be able to get away with less rear spread. A few things to try:
1. lower the whole top bar 1 hole down.
2. Dump air off the shocks as soon as it leaves

The other thing is 46-4800 with that SLR is still what i’d consider a low starting line rpm and I wouldn’t be scared to try 52-5500. Last you might consider a new set of wheelie bars that are shorter(~70-75”) and stiffer to help get the tire turning easier. I’d suggest Trying one at a time and see if it helps. Good luck

I had The front top bar down one hole, and it was good with the four 30s but too violent with the 56s. My last car I had to go to 5500 to get them to even try and spin. I'll see if I can maybe get the IC to around the 58 range. Go figure I had carbon wheelie bars but sold them a while ago

 

Narrowing rear spread takes even more initial bite out.

 

Have any video?

I agree with more rear tire psi being more bite due to contact patch to a point. But the other element is that the rim can’t “ease” into the rest of the tire as it starts to rotate with a lot of air in the tires. The less the sidewalls wrinkle on the transbrake release, the more it strikes the tire into motion, VS easing it into motion. That can help make wheelspeed. Just gotta watch it doesn’t wanna shake when it gets out a little ways. More air makes the wheel and tire act more as one unit VS less air kinda of creating a latency between the two (if that makes any sense). It can also work the other way though with very low pressures. Allowing the rim to get a running start of rotation into the tire, causing it to slam the tire when it winds up and the tread lets go.

Have you tried stiffer rear shock compression? It’ll let the car roll out a little further before the 4 link can start pushing the chassis down, and may let the car get some wheel speed early on.

 

Narrowing rear spread takes even more initial bite out.

Have any video?

I agree with more rear tire psi being more bite due to contact patch to a point. But the other element is that the rim can’t “ease” into the rest of the tire as it starts to rotate with a lot of air in the tires. The less the sidewalls wrinkle on the transbrake release, the more it strikes the tire into motion, VS easing it into motion. That can help make wheelspeed. Just gotta watch it doesn’t wanna shake when it gets out a little ways. More air makes the wheel and tire act more as one unit VS less air kinda of creating a latency between the two (if that makes any sense). It can also work the other way though with very low pressures. Allowing the rim to get a running start of rotation into the tire, causing it to slam the tire when it winds up and the tread lets go.

Have you tried stiffer rear shock compression? It’ll let the car roll out a little further before the 4 link can start pushing the chassis down, and may let the car get some wheel speed early on.

Yes definitely makes sense what you're saying,what I may do to start is move my ic back a little to maybe 58 because I have a 5050 bias so I may be out too far for that kinda weight. Once I do that I may try 7.5psi to see how it handles,worst case is I can pull timing if my wheel speed is too much, and if it isn't enough then I'll increase or decrease tire pressure

 

Hang on,trying to upload video

 

 

I love the flame job on that paint job!

 

Just something to consider, when your guys are backing you up are they getting the tire exact in the burnout? The track prep is so good, if you are exactly in your burnout you'll get a higher tire speed, if you need more traction then set the tire 1/2 in the burnout and 1/2 in fresh track, the tire speed won't be as great with better traction.
If they aren't consistent in backing you up then the launch will be a variable.

 

Just something to consider, when your guys are backing you up are they getting the tire exact in the burnout?
The track prep is so good, if you are exactly in your burnout you'll get a higher tire speed,
if you need more traction then set the tire 1/2 in the burnout and 1/2 in fresh track,
the tire speed won't be as great with better traction.
If they aren't consistent in backing you up then the launch will be a variable.

That's a new one on me.

Isn't that the entire point, hot tire placed over the fresh hot rubber is more traction.
If you are exactly in your burnout you will get lower wheel speed.


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Well I have triple adjustables, I adjusted the high speed four clicks tighter and got the wheel to spin a little on the hit, had some tire shake so went down to 5.5 lb and didn't shake but now my new issue I'm fighting is it starts slowing the tire down about 3 tenths out.
Also as tight as I make the compression, the car still squats exactly 1" every time

 

I know this isn’t always a solution, but shock travel sensors with a velocity channel were a huge help and eye opener for me.

 

I have almost every sensor you could imagine hahaha

I did a 4 link change and got it to squat .850 which is where I want it,graph looked a lot better,now I think I'm very close

 

What’s the velocity when it’s squatting .85?

my car worked best squatting between .8-1.1 inches with a velocity of around 28. I believe that’s inches per second, but don’t remember exactly and it was give or take 5 on velocity.